The pseudophase and compartmental kinetic models of photoreactions in micelles

The scope of two currently used methods to describe the kinetics of chemica l reactions in micellar solutions, the pseudophase and compartmental models , is analyzed. The key criterion of pseudophase model applicability is a sm all (<0.5) ratio between the rate constants for the reaction and for reagen t exchange between phases (this condition is satisfied when the. rate const ant for the reaction is lower than the diffusion constant, and the interpha se distribution coefficient of at least one reagent is smaller than 10(3)). The kinetics of electron phototransfer in sodium dodecyl sulfate micelles was studied for the example of two probes, hydophobic (pyrene) and hydrophi lic [Ru(bipy)(3)(2+)], in the presence of electron accepters and donors wit h different interphase distribution coefficients. Simultaneously, numerical simulations were performed for a wide range of reaction and interphase exc hange rate constants. The difference between the intramicellar rate constan ts for quenching obtained for the pseudophase and compartmental models did not exceed 20% when the intramicellar reaction rate constant was smaller th an the rate constant for escape of reagents from micelles.